Generally, a motor and fan are provided which draw fluid into a body; the fluid may be heated prior to exiting the body. The motor is susceptible to damage from foreign objects such as dirt or hair so conventionally a filter is provided at the fluid inlet to the blower. The fan and heater require power in order to function and this is provided via internal wiring from either a mains power cable or batteries attached to the appliance.
Thermal protection is conventionally provided in the form of a thermal cut-out such as a bi-metallic strip or a thermal fuse. Thus, if the fluid flowing exceeds a pre-determined limit, the bi-metallic strip will break contact or the thermal fuse will melt, both causing a break in the electrical circuitry to the heater element.